SCOTTSDALE, Ariz. -- Georgia quarterback Aaron Murray looked like a rag doll after the hit. He convulsed and flopped to the ground.

Auburn defensive tackle Nick Fairley delivered the devastating blow, charging from behind Murray and spearing him in the back. Fairley was penalized for the hit.

It definitely was a vicious hit -- a cheap shot, some said. And it was one of several big blows Fairley delivered against Georgia, and they only fueled the perception that Fairley is a dirty player.

"I'll tell you what: Our offensive line coach said he is by far the dirtiest player in the SEC," said an SEC assistant who wished to remain anonymous. "I think that reputation is warranted from what happened in the Georgia game."

In the second quarter of the game, Fairley came in hard on Murray after a pass, picked him up and drove him hard to the ground. Later in the fourth quarter, Fairley rolled into Murray's left knee on a pass rush long after the ball had left his hand. In the waning moments of the game, some Georgia players went after Fairley, with both benches emptying and coaches having to restrain players. Two Auburn players were ejected following the ruckus: defensive linemen Michael Goggans and Mike Blanc.

Georgia coach Mark Richt was asked after his team's loss to Auburn if he was unhappy that Fairley had hit Murray late on several occasions. "I'm not going to answer that question," he said.

Fairley denies that he's a dirty player.

"I'm a hard worker," Fairley told Rivals.com on Thursday, when he met with the media gather for Monday's BCS national championship game. "I'm ready to go. The motor is always running."

Oregon definitely will be aware of Fairley, a 6-foot-5, 298-pound junior who is the best defensive tackle in the nation and the SEC Defensive Player of the Year. He leads the SEC and set the Auburn single-season record for tackles for loss with 21. Fairley also is second in the SEC in sacks with 10.5.

Fairley originally signed with Auburn out of Mobile (Ala.) Williamson in 2007. But he had academic issues and instead went to Copiah-Lincoln CC in Wesson, Miss., and signed with Auburn again in 2009.

"I knew he had tremendous ability," said Copiah-Lincoln coach Glenn Davis, who also has coached NFL players Walter Jones and Tony Bryant. "The first year, we really didn't know that much. A lot of things came easy for him. He wasn't really pushed here. He was so much more athletic than everyone.

"When he really wanted to play, he was dominant."

But is he really a dirty player?

"I don't think he's a dirty player," said an SEC defensive coordinator who asked for anonymity. "I think he's an aggressive player. They don't emphasize hitting the quarterback in college like they do in pro ball.

"I think he's an aggressive, get-after-it kind of kid. The good ones? Some of those guys are going to be on the edge, now. That's kind of what makes them good. I just think he plays hard and has made a big impact on their defense."

Former Mississippi State defensive coordinator Manny Diaz, who earlier this week accepted the same job at Texas, agrees. "I haven't seen anything," Diaz said. "When we played them, we could barely put a hand on the guy. He has had games where he is unblockable."

Fairley needs to be his usual disruptive self as the Tigers try to slow an Oregon attack that ranks No. 1 in the nation in total offense (537.5 yards per game) and scoring offense (49.3 points per game).

"He's a special player," said Auburn defensive coordinator Ted Roof, who has been a college assistant since 1989. "He can make things happen in the middle of the line, pushing the pile. He's a difference-maker."

On the defensive

Auburn is trying to become the fifth consecutive SEC team to win the national title. In each of the past four title games, the SEC team has received big games from some key defensive linemen. Here's a look:

2006

Florida: The Gators held Ohio State to 82 total yards, including just 47 on the ground, in a 41-14 rout. E Derrick Harvey had three sacks, E Jarvis Moss had two sacks and T Ray McDonald had three tackles.

2007

LSU: The Tigers had five sacks in beating Ohio State 38-24. The Tigers built a 28-10 lead before cruising home. E Kirston Pittman had seven tackles and a sack, E Ricky Jean-Francois had six tackles and 1.5 tackles for loss and T Glenn Dorsey had five tackles and a sack.

2008

Florida: The Gators held a record-setting Oklahoma offense to 14 points in a 24-14 win. The Sooners managed just 107 rushing yards. E Carlos Dunlap had four tackles and 1.5 tackles for loss, T Lawrence Marsh had three tackles and T Torrey Davis had a huge tackle for loss on a 4th-and-goal from the 1 late in the first half.

2009

Alabama: The Tide held Texas to 276 total yards and 81 yards on the ground in rolling to a 37-21 win. E Marcell Dareus had an interception return on the last play of the first half that gave the Tide a 24-6 lead. Ts Josh Chapman and Terrence Cody had three tackles each and E Lorenzo Washington had 1.5 tackles for loss.

Fairley must get penetration to disrupt the timing of the high-powered Oregon attack. It was a formula that Cal used in coming the closest of any team to knocking off the Ducks this season, losing 15-13. The Golden Bears limited Oregon to 317 total yards, including just 162 on the ground.

"When you get ready to play Auburn, they guy you notice is Nick Fairley," Kentucky offensive coordinator Randy Sanders said. "When he makes up his mind to not be blocked, he doesn't get blocked. They will have to do a good job managing him so he isn't disruptive.

"It is harder to deal with a d-tackle than it is a linebacker or an end. When they push the pile back in the middle, it makes you run outside. And when they know where you're going, it's easier to stop."

Oregon uses zone blocking schemes instead of straight man-on-man work from its offensive line; that means a lineman is responsible for clearing an area and not necessarily a specific player. That makes Fairley's first-step quickness a potential huge problem for the Ducks.

Davis noticed Fairley's quickness early on. An offseason workout had just ended and Davis let his Copiah-Lincoln players play some basketball to warm down.

"Out of the corner of my eye, I saw this flash," Davis said. "It was Nick Fairley. He went up to get a rebound, grabbed the ball and slammed it without touching the ground. It looked like his elbow was touching the rim. That's when I said: 'We have someone special here.' "

When Auburn sent Fairley to Copiah-Lincoln, the coaches thought he might be a great offensive tackle. But the Copiah-Lincoln staff played him on defense because he was more athletic than anyone they had. Tommy Tuberville was the Auburn coach when the Tigers originally signed Fairley.

"From the little I saw of him this year, he was a good as I've seen in a long time," said Tuberville, who just finished his first season at Texas Tech. "He reminded me of Warren Sapp. He had great explosion, good first step."

The play that perhaps epitomized Fairley's dominance came late in the first half against Alabama. The Crimson Tide led 24-7 and were in the shadow of Auburn's end zone, threatening to make their lead even bigger.

That's when Fairley cut through the guard-tackle hole, sacked Tide quarterback Greg McElroy and caused a fumble. For good measure, Fairley also recovered the fumble. Auburn then mounted a furious second-half rally to pull out a 28-27 win that kept the Tigers' national title hopes alive.

"The play he made basically won the game," Tuberville said. "They were ready to go up really big and he sacks the quarterback, causes a fumble and recovers it. That was about as good a play on defense I had ever seen."

Fairley couldn't have made that play last season. For all his physical tools, he underachieved last season as a third-year sophomore with the Tigers (he only played one season of football in junior college). Fairley made just two starts in 2009, finishing with 28 tackles, 3.5 tackles for loss and 1.5 sacks. Roof has admitted he blasted Fairley for his work ethic, and Fairley took the criticism to heart and blossomed into a full-fledged star.

"You better be aware of him and get four hands on him," Ole Miss coach Houston Nutt said. "He's tough."

But is he dirty?

"Nick is not a dirty player," Auburn safety Zac Etheridge said. "I mean, it's football. You put on pads, and it's a collision sport. There are no friends on the field. That's how you have to play.

"No, he isn't a dirty player. He plays the game the way it should be played."